Aromatization catalyst, light

Drake, C.A. (1998) Improved catalyst composition useful for conversion of non-aromatic hydrocarbons to aromatics and light olefins. WO Patent 98/51409. 

One Interesting and industrially important process developed recently,"the cyclar process" is the catalytic aromatization of light (C3-C5) hydrocarbons over pentasil based catalysts. These new classes of solids have been widely studied (1-9). These Investigations led to the conclusion that the catalysts consisting of gallium, zinc, Pt, and modified H-ZSM-5 were more active and more selective towards aromatics than the parent H-ZSM-5 zeolite. The formation of aromatics from light alkanes comprised several main hydrocarbon reactions alkane... 

Deactivation of light naphtha aromatization catalyst based on zeolite was studied, by kinetic analysis, micropore volume analysis and model reactions. Coke accumulates at the entrance of zeolite channel, blocks it and hinders reactant molecule to access active sites in zeolite channel. Our own stabilization technique passivates coke-forming sites at the external surface of the zeolite. This minimizes the coke formation at the entrance of zeolite channel and increases on-stream stability. The stabilized catalyst enabled us to develop a new light naphtha aromatization process using an idle heavy naphtha reformer that is replaced by CCR process. 

FUKASE ET AL. Deactivation of Light Naphtha Aromatization Catalyst 221... 

A new catalyst with long-term stability was developed for the aromatization of light naphtha. Our proprietary technique of steaming reduced acid site density of the external surface of the catalyst and minimized coke formation. The new catalyst enabled us to develop a new light naphtha aromatization (LNA) process using a conventional fixed bed unit. Idle heavy naphtha reformer can be converted to this process without large modification. 

Life Testing of Light Hydrocarbon Aromatization Catalysts... 

Catalyst life estimation tests were also conducted on four different catalysts used for aromatization of light hydrocarbons in this system, namely H-ZSM-5, Zn/H-ZSM-5, Ga/H-ZSM-5 and H-Ga-silicate. Based on the results of characterization of the spent catalysts, the primary cause of deterioration of catalyst activity is the elimination of active metal from the zeolite framework. 

The reaction of aromatization of light petroleum fractions over Pt/Al203 is poorly known. Therefore, the investigation of this reaction over complex multi-component catalysts containing platinum is a subject of a great interest. 

Price, G. L. and Kanazirev, V., The oxidation state of Ga in Ga/ZSM-5 light paraffin aromatization catalysts, Journal of Molecular Catalysis 66, 115-120 (1991). 

Ga exchanged H-ZSM-5 is a proven catalyst for aromatization of light alkanes (C3 and C4) and is applied in the CYCLAR process [102], They act in this reaction as bifunctional catalysts with gallium species promoting the activation and dehydrogenation of the alkane and acid centers, where the polymerization... 

Cu-ZSM-5 catalysts for the aromatization of light paraffins and conversion of 1 -propylamine were prepared via SSIE by Kanazirev and Price [110,111] (cf. also Sects. 6.3.3.2 and 6.3.3.3). 

---